Lumen reduction measurements of the internal carotid artery before and after Levovist enhancement: Reproducibility and agreement with angiography

Our aim was to assess reproducibility of three different lumen reduction me asuring methods-North American Symptomatic Carotid Endarterectomy Trial, Eu ropean Carotid Surgery Trial, and common carotid-using power Doppler and co lor Doppler sonography and after Levovist enhancement. We included 20 symptomatic patients with mild or severe carotid disease. No rth American Symptomatic Carotid Endarterectomy Trial, European Carotid Sur gery Trial, and common carotid measurements on longitudinal views and Europ ean Carotid Surgery Trial measurements on transverse views were performed. Examinations were repeated and the results compared to assess reproducibili ty of measurements. Correlation with angiography was obtained by calculatin g Pearson correlation coefficients. Reproducibility was significantly better (P < 0.05) for European Carotid Su rgery Trial and common carotid measurements (95% limits of agreement betwee n -10% to 10% and -19% to 17%) as compared to North American Symptomatic Ca rotid Endarterectomy Trial measurements (95% limits of agreement between -1 1% to 21% and -21% to 23%). Variability of measurements after enhancement i ncreased slightly (not significant) for both power and color Doppler sonogr aphy. Additionally, European Carotid Surgery Trial measurements, using none nhanced power Doppler or color Doppler sonography, did not correlate signif icantly with angiography, whereas North American Symptomatic Carotid Endart erectomy Trial and common carotid measurements correlated well with angiogr aphy, particularly in power Doppler mode after enhancement (r = 0.88 and r = 0.82, respectively). We conclude that for lumen reduction measurements of the internal carotid a rtery with power and color Doppler sonography, the common carotid method is the only method that is reproducible and has good correlation with angiogr aphy,which slightly improves after Levovist enhancement.